Fuel-supply system for explosive-engines.



H. LEMP. FUEL SUPPLY SYSTEM FOR EXPLOSIVB ENGINES.

APPLICATION FILED MAY 23, 1906.

Patented May 7, 1912.

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HERMANN LEMP, 0F LYNN, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTRIC COM- PANY, A CORPORATION OF NEW YORK. I

FUEL-SUPPLY SYSTEM FOR EXPLOSIVE-ENGINES.

Specification of Letters Patent.

Patented May '7 1912.

Application filed May 23, 1906. Serial No. 318,338.

To all whom it may concern Be it known that L'HERMANN LEMP, a citizen of the United States, residing at Lynn, county of Essex, State of Massachusetts, have invented certain new and useful Improvements in Fuel-Supply Systems for Explosive-Engines, of which the following is a specification.

The present-invention relates to fuel supply systems for explosive engines, especially those used on automobiles, launches, etc.

Automobile engines are commonly supplied with gasolene by means of a float feed carbureter comprising a chamber containing a float that is attached to a valve, the latter regulating the admission of gasolene to the chamber and to the engine. Connected with the chamber, and between it and the engine,-

is a nozzle for supplying the necessary amount of gasolene to the air, as the latter I flows past itto form an explosive mixture of the proper character. The float feed mechanism of this type of carbureter has always been a delicate piece of apparatus and uncertain in its operation, and therefore a source of'trouble, largely because the variations in pressure due to the suction of the piston of the engine are slight. Moreover, the carbureter either has to be supplied by gravity from a tank, which is sometimes diflicult to arrange in an automobile, by air pressure, requiring attention on the part of the operator when the tank is situated below the carburetor, or by the exhaust of the engine.

The object of the invention is to overcome the disadvantages set forth above by dispensing with the float fed mechanism and its uncertainty of operation, and to substitute therefor a suitable chamber for feeding the spraying nozzle which is constantly supplied with gasolene in excess of the requirements, the said chamber being provided with an outlet at a given elevation so that the excess gasolene at any given time is carried off, as for example, by being returned to the supply tank.

A further object of the invention is to provide, in addition to the foregoing, a means for positively forcing gasolene from the supply tank into the chamber so that the tank can be placed wherever it is the most convenient and accessible, either above or below the said chamber.

" panying In carrying out my invention, a vessel'is provided containing a chamber of suitable size thatis connected to the sprayingnozzle,

and also to the source of supply. Communicating with the chamber in the vessel, is an outlet or overflow through which the excess gasolene is returned to the supply tank. The outlet or overflow is preferably adjust able as to elevation, and is commonly set slightly below the discharge end of the spraying or discharge nozzle. Gasolene is conveyed from the supply tank to the vessel by a pump which is so constructed and arranged that it is adapted to operate by the variations of pressure in the explosion or working cylinder of the engine, as for example, the explosion pressure causing the discharge stroke of the pump, and the suction pressure the suction stroke This ar-, rangement obviates the use of working members connecting the piston of the pump with the crank shafts or other part moving with or driven by the engine. Furthermore, the pump can be located point. By preference, I locate it below the level of the fuel tank so that its valves are normally flooded. The pump is of the diaphragm type and is of suflicient capacity to at any convenientsupply on each stroke an amount exceeding f the maximum demand of the carbureter, the surplus being returned or by-passed to the tank. This insures an abundant supply for the maximum demand at all times and by means of the free by-pass the possibility of flooding the carbureter is prevented. The pump can be so designed as to output, that a substantially continuous flow can be maintaihed so that a single pump will be suflicient for an engine of any number of cylinders.

The invention is also applicable to stationarygas engine plants, since by means of the pump the source of fuel supply can be isolated from the building insurance regulations and laws.

For a more detailed understanding of the organization and mode of operation of the invention, as well as the features of novelty, reference is to be had to the accomdescription and claims appended hereto. t

In the accompanying drawing, which illustrates one embodiment of which. the invention is capable, Figure 1 shows a fuel to comply with supply system applied to a gas engine, the

latter being only partially shown; Fig. 2 is a section of the pump taken on the line 2 2,

Fig. 1; and Fig. 3 is a detail sectional view of the pump.

Referring to' the drawing, 1 represents a portion of an explosive engine, to the cylinder or cylinders of which the fuel charges ,are supplied through the inlet conduits 2.

These conduits connectwith an air suction conduit 3 in which is located the carbureter 4-. The open end of the conduit 3.isnot shown but the air enters in the usual manner through a suitable screened opening and flows 1n, the direction indicated by the ar- The carbureter comprises a mixing chamber 5 containing a spray nozzle 6, through which chamber the air passes. The nozzle communicates with a fuel-containing chamber ,7 and receives fuel therefrom. The

7 quantity of fuel discharged by the nozzle is valve shown valve 18, Fig. 3. Th opposite .side of the controlled in the usual manner by a needle at 8 andthe amount of air or mixture may be controlled by a throttle valve 9, the details of which'are not essential to an understanding'of the presentinvention.

Suitably located with respect to the carbureter, preferably below the same so that any surplus fuel may be returned'thereto by gravity, is a fuel tank 10 whicli connects vlvlith ttile fuel chamber 7 of 21:16 ciarburefller t rou the supp y pipe 11. n t e supp y pipe a pump'12 by which the fuel is fed ositively to the carbureter. Referring to ig.. 2 the pump,comprises a casing 13 formed of two disks bolted together and shaped to form a shallow chamber. In the chamber, and dividing it into ments, is arranged'a diaphragm 14 secured at its edge between the disks. -One compartment communicates through the pas-. sages 15 and 16, Figs. 2 and 3, with the sup? ply pipe 11, and as the diaphragm moves ack and forth, fuel is drawn into the com- At the ends ofthe passage 16 are formed valve chambers in which are located, respectively, a suction valve 17 and a delivery e compartment on the diaphragm communicates with the compression space or combusthe conduit upon. the diaphragm and moves tion chamber of the: engine cylinder through the conduit 19. By virture of this, when the re in the engine cylinder reaches acertainipoint, as for instance at the time of explosion, the fluid pressure acts through it to the right, Fig. 2. This forces out the charge of fuel previously drawn in the compartment on the right side of the diaphragm. When the pressure on the engine cylinder falls sufliciently, as durin the sliction stroke or the diaphragm returns or two compartduring the period 0 exhaust,- moves to th left' and draws in a charge of fuel. This suction stroke may be due entirely to the fall in pressure in the engine cylinder or it may be caused by a spring or bya normal bias imparted to the diaphragm. Interposed in .the conduit 19-, andwbetween the diaphragm and the engine cylinder, is a small body of viscous substance, such as glycerin, which serves to prevent the hot gases affecting the diaphragm.

In the fuel-containing chamber of the carbureter is an overflow pipe 20 around which is threaded a sleeve 21 forming a dam that can be adjusted to vary the height of the fuel for obtaining the proper level at the spraying nozzle. The over-flow pipe is connected to the tank 10 by means of the conduit 22. The upper end of the pipe 20 is surrounded by a cylindrical wall 20 to reduce the effect of splashing in the chamber. The pump is so designed as to give an output exceeding the amount that is discharged at the spraying nozzle during each suction stroke amount over-flows and returns to the tank. It will thus be seen that any change in the level of the parts of the vehicle will not affecttheamount of fuel discharged from the spraying nozzle, and furthermore, there is always sufiicient fuel present in the fuelcontaining chamber 7 to meet the maximum demand. In order to equalize the pressure within the fuel-containing chamber and to admit air a screened vent 23 is provided. To fill the carbureter and the tank a filling pipe 24 having a shut-off valve 25 is employed, which for simplicity connects wit-h the supply pipe 11 adjacent the carbureter. In some systems a reserve tank or reservoir may be provided, preferably located above the level of the carbureter, and the pipe 24 is connected therewith to receive the fuel under gravity. If no such reserve tank is employed the fuel is supplied to the filling pipe in the usual manner. In the filling process the needle valve 8 of the carbu'reter is first closed and then the valve 25 opened. Fuel thereupon flows into the chamber 7 of the carbureter and after filling the same to its normal height over-flows and fills the tank 10. is full an overflow or-stand-pipe 26 is used which also serves as a vent to admit air as the pump draws ofi the fuel. The opening of this pipe is preferably fitted with a screen to protect the tank in case of accident from flames. After the carbureter and tank are filled, the valve 25 is closed and the needle valve 8 opened to supply the charge as soon as the engine is started. Immediately upon starting the engine the pump is operated, since the diaphragm chamber thereof is in permanent communication with the interior of/theengine cylinder.

In accordance with the provisions of the of the engine and the excess To indicate when the tank patent statutes, it have described the princi le of operation of my invention, together with the apparatus which ll now consider to represent the best embodiment. thereof; but ll desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What ll claim as new, and desire to secure by Letters Patent of the United States, is,-

1. The combinatianwith an explosive engine, a carbureter therefor comprising a mixing chamber, a fuel containing chamber, a spraying nozzle in the first' chamber to which fuel fiows by gravity from the second chamber, and an overflow pipe in the second chamber which determines the level of the fuel in said chamber with respect to the height of the spraying nozzle, of a fuel tank a connection between the overflow pipe and the tank which constitutes a by-pass, and a diaphragm pump between the and the tank which is operated by pressure transmitted from the combustion chamber "of the engine, said pump being located adjacent to the tank and below the levelthereof chamber with respect to .pump between carbureter so that fuel will ow by gravity to the pump and lreep it flooded with fuel.

2. The combination with a carbureter comprising a mixing chamber, a fuel con vtaining chamber, a spraying nozzle in the mixing chamber to which the fuel fiows by gravity from the second chamber; and an overflow pipe; i;r 1 ,the second chamber, which determinesthe level of the fuel in said spraying nozzle, of a fuel tank, a connection between the overflow pipe and the tank which constitutes a bypass,. a diaphragm the carbureter and the tank which is operated by fluid pressure and to which the fuel flows by gravity from the tank, and a filling device so locatedand arranged as to first fill the fuel-containing chamber of the carbureter and thereafter fill the tank through the by-pass.

In witness whereof, I; have hereunto set my hand this fifteenth day of May, 1906. HERMANN- LEMP. Witnesses:

JOHN A. McMANUs, Jr., Jorm J. WALKER.

the height of the 

